Senator Cory Booker was photographed holding a sign bearing a pro-Palestinian movement slogan. The image appeared on the Twitter feed of the U.S. Campaign for Palestinian Rights, a self-described “coalition of 330+ groups” working “for a US policy toward Palestine/Israel based on freedom, justice, and equality.”

“From Palestine to Mexico, all the walls have got to go,” the sign read.

Booker, however, claims he wasn’t aware that the sign called for an end to the border wall between Israel and the Palestinian territory, but rather only a U.S. border wall with Mexico.